1. Field of the Invention
The present invention is directed to a device for fastening objects to a concrete surface, and more particularly to a device for temporarily fastening wooden forms to a concrete surface.
2. Brief Description of the Prior Art
The prior art is well aware of the process of manufacturing a concrete wall or wall section on a substantially flat, hard concrete surface. More particularly, it is established practice in the construction industry to pour several walls or wall sections of a building on a previously poured and hardened concrete foundation of the building under construction.
In order to make a wall section in the above described manner, an area of the concrete foundation which corresponds to the dimensions of the desired wall section is fenced off by a plurality of wooden forms. The wooden forms are attached to the concrete foundation so as to prevent their dislocation, particularly their dislocation in a lateral direction. The surface of the concrete foundation is wetted with a suitable hydrocarbon fluid, such as diesel fluid, in order to prevent adherence of the newly formed concrete wall section to the concrete foundation. Concrete mix is then poured into the area fenced off by the wooden forms. After hardening of the newly poured concrete, the wooden forms are removed and the concrete wall section is lifted off the foundation for incorporation into the building.
According to usual practice in the prior art, wooden fastener members are used to prevent lateral dislocation of the wooden forms on the hard concrete surface. These wooden fastener members usually comprise two boards attached to one another at a right angle. A first, horizontally disposed board of the wooden fastener member is placed upon the concrete surface. A second vertically disposed board of the fastener member abuts, with its narrower side, the wooden form. A plurality of holes or apertures are drilled through the first board into the concrete surface. Nails are inserted through the horizontally disposed board into these apertures to temporarily hold the wooden fastener member in place.
The prior art has also used metal fastener members for temporarily fastening the wooden forms to the concrete surface. The metal fastener members of the prior art comprise two metal surfaces or plates which are disposed at a right angle relative to one another. Holes or apertures are usually provided in both metal plates for inserting nails respectively into the concrete surface and into the wooden form. In one particular embodiment of a metal fastener member of the prior art, a wooden dowel is fitted into a horizontally disposed plate of the fastener member. In the process of attaching the fastener member to the concrete surface, a hole is drilled through the wooden dowel into the concrete surface, and a nail is inserted. One or more nails are then driven into the wooden form through apertures provided on a vertically disposed plate of the fastener member.
It is also established practice in the prior art to provide a circular aperture in the horizontally disposed plate of the metal fastener member through which a somewhat smaller aperture may be drilled into the concrete surface. These apertures may be dimensioned to accommodate more than one nail. Usually two or three nails are force fitted into the pre-drilled aperture in the concrete. The several nails forced into the single aperture usually provides an attachment of greater strength than a single nail simply inserted into a predrilled hole.
It is readily apparent to those familiar with the construction industry that an operator must be able to attach the fastener member to the concrete surface and to the wooden form in a relatively short period of time, preferably within a few seconds. Moreover, it is highly desirable that the fastener member be reusable and therefore readily removable both from the concrete surface and from the wooden form.
It has been the experience of the prior art that wooden fastener members are relatively expensive to manufacture. Furthermore they are all too often damaged or destroyed while they are being removed from the concrete surface. Although the metal fastener members of the prior art are resuable, they usually have not been attachable to the wooden forms in a desired short period of time. For the above stated reasons, there is still a need in the prior art for an improved fastener member having the features of the fastener member of the present invention.